1. Field of the Invention
The present invention relates to a cooling system and its cooling elements. More particularly, the present invention relates to a heat pipe cooling system and a thermal connector thereof.
2. Description of the Related Art
To remove the heat produced by a heat-generating device in operation and prevent over-heating due to the rapid accumulation of heat around the heat-generating device, a heat sink is often attached to the surface of the heat-generating device. Furthermore, a fan is also used to force a stream of air over the heat sink and produce a convective current that carries the heat away from the heat sink and prevents the over-heating of the device.
However, as the quantity of heat generated by the device is increased, the conventional heat dissipation method will become a bottleneck. To match the increase in heat production by a heat-generating device so that the device can operate within a normal operating temperature range, the conventional technique demands an increase in the total surface area of cooling fins on the heat sink or the rotational speed of the fan. Yet, if the heat-generating device is disposed inside the limited space of an enclosed housing, then increasing the surface area of fins will increase the spatial occupation of the cooling fins. On the other hand, if the rotational speed of the fan is increased to provide a more forceful convection, more vibration and noise will be produced in addition to an increase in energy consumption.
In recent years, a thermal device that conducts heat away through the phase change in a working fluid has been developed. These phase-change thermal devices include two major types: the loop heat pipe and the capillary pump loop, for example. To carry heat away from a heat-generating device, the working fluid in an evaporator absorbs the heat and changes into a gaseous phase. A capillary structure separates the liquid working fluid and the gaseous working fluid. A sufficiently powerful pressure differential is established between the inside and outside of the capillary structure. Then, the pressure differential drives the working fluid to recycle in the loop system. In the recycling process, the heat absorbed by the gaseous working fluid is released inside a condenser so that the working fluid returns to a liquid phase. Because the capillary structure inside the thermal device can produce a sufficiently large capillary force to resist the friction of the working fluid flowing inside the thermal device, the phase-change thermal device is able to carry heat away from a heat source over a long distance to a condenser.
For example, when a central processing unit (CPU) is disposed inside a limited space within a computer casing, the phase-change thermal device can carry the heat produced by the CPU through a pipeline to a suitable location where heat can be dissipated. Thus, the heat-dissipating device is no longer constrained by the limited space inside the computer casing. Other advantage of the heat pipe cooling system includes a sturdy package, a high thermal conductive capacity, a flexible pipeline routing, a power source free operation and an operation unaffected by gravity.